The present invention relates to a method for creating a material library of surface areas having differing properties.
A method of this type is known from practice and is used in the field of surface coating technology.
In one familiar method of the type cited above, representing a combined method, a surface of a substrate, for example, the surface of a ceramic, is coated in differing areas using differing substances, i.e., coating materials. The individual areas, each coated in a different manner, have different chemical and/or physical properties, which are a function of the specific coating material.
In addition, it is known to influence the physical, or chemical, properties of a substrate that is coated using a coating material by pretreating the substrate before the coating is applied. This can be done, for example, using liquids or gases.
The method according to the present invention for creating a material library of surface areas having differing properties in which the substrate is subjected to a combined pretreatment procedure, has the advantage that within a brief time after an automated procedurexe2x80x94for example, using a robotxe2x80x94the substrate can be pretreated in an area-specific manner, and therefore areas can be generated having the most widely varying chemical and/or physical properties.
This pretreatment procedure, which is carried out before the coating of the substrate is applied, is especially advantageous if the physical and/or chemical properties of a surface system, composed of a substrate and a coating, are optimized with respect to specific parameters. For example, the substrate can include many dozens of defined areas, each of which is subjected to a different pretreatment.
The substrate to be pretreated can be any material, for example, a glass, a ceramic, a metal, or a plastic.
The combined pretreatment procedure, which is advantageously carried out in an area-specific manner, can include a treatment of the substrate using varying liquids and, in another embodiment, can include a treatment using varying gases. Of course, it is also conceivable to pretreat certain areas using a gas and other areas using a liquid.
The liquids can be, for example, sodium chloride solutions, sodium hydroxide solutions, and hydrochloric acid solutions of the most widely varying concentrations.
As pretreatment gases, for example, ammonia, carbon dioxide, and/or hydrogen can be used. In this context, the gas pressure can be varied.
It is also conceivable to subject the substrate in specific areas to an epitaxial vapor deposition procedure as a pretreatment.
Alternatively or additionally, the combined pretreatment procedure can also include area-specific sputtering processes, in which different materials are applied in different areas of the substrate. In this specific embodiment, the substrate functions as a base substrate. The deposited materials and the substrate, which functions here as a base substrate, in turn constitute the workpiece that is coated.
Moreover, the combined pretreatment procedure can include area-specific heat treatments. This means that the substrate in different areas is subject to different heat treatments. In this context, the duration of the heat treatment and/or the temperature applied in each case are varied from area to area.
The substrate can include heater patterns. This is especially advantageous if the combined pretreatment procedure includes area-specific heat treatments. The heater patterns can in turn be designed within the substrate so as to be different in specific areas. These differences can be achieved by varying an imprinted heater pattern with regard to its imprinting width and/or its number of printed circuit traces.
Alternatively, the area-specific heat treatments can be carried out using a laser. For example, one area of the substrate can be irradiated for 10 minutes, and another area of the substrate can be irradiated for 5 minutes. This can result, for example, in these two areas having different heat conductivities.
The pretreatment can thus be carried out in a fundamentally wet-chemical manner, using gases, in a thermal manner, or even using solid-dosing. It is, of course, also conceivable that individual areas of the substrate are subjected to different pretreatments, for example, a wet-chemical and a thermal pretreatment.
To be able to carry out the combined pretreatment procedure in a controlled, area-specific manner, it is advantageous to use a mask, preferably a Teflon mask. A mask of this type makes it possible, e.g., in the application of lacquer, to use a greater quantity of liquid than would be the case in an application by drops, without a mask.
According to one advantageous embodiment of the method in accordance with the present invention, the substrate is coated using a selected surface material. Using this surface material, the target variable that is necessary as a function of the application area can then be tested. The target variable can be, for example, the surface hardness, the resistance to tearing of the coating, or the structural properties of the system composed of the coating and the substrate. The analysis of the properties is carried out using the usual measuring methods.
The coating of the substrate having the surface material can be applied over the entire surface. In this case, in accordance with one advantageous embodiment of the method according to the present invention, the coating is applied using spin-on deposition.
However, the coating having the surface material can also be applied in patterns. This means that the substrate is coated using the surface material in an area-specific manner. By way of example, the mask used for the combined pretreatment can be employed for this purpose. For example, the coating can be applied in drops onto the substrate in an area-specific manner.